1. Field of the Invention
The present invention relates to a method of manufacturing an organic light-emitting device having an organic electroluminescence (EL) element.
2. Description of the Related Art
In recent years, display devices of the next generation are actively developed, and smaller space, higher brightness, lower power consumption, and the like are in demand. As such a display device, attention is being paid to an organic light-emitting device using an organic electroluminescence element. The organic light-emitting device has characteristics such that since it is of a light-emitting type, the view angle is wide, backlight is unnecessary, so that power consumption is expected, response is high, and the device is thin. Consequently, application to a large-screen display device such as a television is strongly demanded.
The organic electroluminescence element has an organic layer including a light emission layer between an anode and a cathode. The methods of driving the organic electroluminescence element include: a simple matrix driving method of controlling light-on and light-off of any of pixels arranged in a matrix by a voltage applied to a cross point between a selected line and a signal line; and an active matrix driving method of controlling light-on and light-off of any of pixels arranged in a matrix by a switching element corresponding to the pixel. In the active matrix driving method, the anode is connected to one of signal terminals of a TFT (Thin Film Transistor) as a switching element.
In such a process of manufacturing an organic light-emitting device, in some cases, a pin hole or the like is formed in a thin organic layer due to a small particle or the like. The pin hole or the like becomes an area where an electric short circuit occurs between the anode and the cathode sandwiching the organic layer. All or part of the current to be passed to the organic layer flows to the short-circuit area. As a result, a phenomenon occurs such that the organic electroluminescence element does not emit light or becomes dark. A pixel in which such the phenomenon occurs is recognized as a display defect. To avoid the phenomenon, various methods are proposed.
As an example of a method of related art, an organic electroluminescence element is formed and, before a protection film or a sealing layer is formed, aging is performed. The short-circuit area is repaired by using a self healing phenomenon (refer to, for example, Japanese Unexamined Patent Application Publication No. 2003-173873 (patent document 1) and Japanese Patent No. 3,575,468 (patent document 2).